Transgenerational effects of ocean warming and acidification on developmental stages of the purple sea urchin Strongylocentrotus purpuratus

Sam Karelitz¹, Daniel Okamoto¹, Maya Munstermann¹, Nathan Spindel²

¹University of California Berkeley, USA - ²San José State University, USA

Global change and extreme climatic events are putting pressure on organisms to acclimate or adapt to new and unpredictable environments. For many species, early development represents the most vulnerable life-history stage to environmental stress. Transgenerational plasticity is suggested to buffer offspring against stressful conditions, yet little is known about their effects across developmental stages. We examined transgenerational effects on thermal tolerance and sensitivity to temperature and high pCO2 in early development and larval stages of the purple sea urchin Strongylocentrotus purpuratus. Adult urchins were conditioned in control (13°C/600 μatm), high temperature (18°C/600 μatm), and high temperature combined with high pCO2 (18°C/1200 μatm) treatments prior to spawning. Parental acclimation to 18°C resulted in greater thermal tolerance during embryogenesis and early larval development. Yet, these effects largely manifest outside of the conditions presently experienced by larvae in nature. Rather, when simulating present-day conditions, growth and long-term larval survival showed little influence of parental conditioning. Instead, responses were largely driven by conditions experienced by larvae. Larvae raised in 18°C treatments were larger than those raised at 13°C but also experienced the highest mortality rates with little to no effect of parental treatment. Our study shows that although transgenerational effects were evident in early development at the most extreme conditions, the environment experienced by larvae had the greatest effect on growth and survival.